Renewable electric fuse



March 21, 1933.. c. KEMP ET AL RENEWABLE ELECTRIC FUSE Filed July 3, 1931 e72; 58 7? INVENTOR.

a ATTORNEY Patented Mar. 21, 1933 PATENT OFFICE CHARLES KEMP AND IE'QRJN'IEIS'I. KEMP, OF BLOOMFIELD, INDIANA RENEWABLE ELECTRIC FUSE Application filed July 3,

The invention relates to electrical apparatus, particularly to fuses for the protection of various types of installations, and has for its principal object the provision of a novel type of fuse which may be described as renewable inasmuch as it embodies a plurality of fuse elements which may be successively and selectively brought into operative position as occasion may demand.

It is well known in the art that it is a common practice to provide in lighting and other installations, a fuse of some sort or other which is adapted to break the circuit in the event of an overload such for instance as is caused by a short circuit. It is also well known that the ordinary type of fuse comprises an insulating body having a central contactand an outer contact formed as a ring member both of which are connected by a piece of wire or other metal which is adapted to melt or fuse at a certain predetermined temperature produced when there is ashort circuit in a line. Whenever the ordinary type of fuse is blown the circuit is of course broken and it therefore becomes necessary to replace the blown fuse with a new one. As new ones are not always available and as each one costs a certain amount considerable annoyance results from this sitnation.

It is with the above fact in view that We have devised the present invention which has for its obj cct the provision of a fuse plug which is adapted to replace one of the ordinary type and which is provided with a plurality of fusible elements adapted to be brought successively into the circuit as one or another burns out or is melted so that y the circuit will be restored without its being necessary to insert a brand new fuse device in ihe socket provided for the reception of suc Another object of the invention is to provide a renewable fuse device which is adapted to be screwed into the ordinary socket and which embodies a rotary element carrying a plurality of fusesadapted to be brought I successively into the circuit as one or another may melt or burn out, it being quite clear that there is a great savin in the cost 1931. Serial No. 548,635.

of maintenance and a considerable saving in the cost of the fuse devices themselves inasmuch as one constructed in accordance with our invention is adapted to take the V place of six or more of the ordinary variety.

Another object of the invention is to provide a device of this character which is provided with means whereby when the rotary element is turned to bring the successive used elements into position positive stop means is provided which will operate to maintain the proper position to establish a circuit.

An additional object is to provide a device F a of this character which is of such construction that when all of the fusible elements have become blown out or melted it is merely necessary to provide a new rotary member carrying the fuse elements, thereby additionally making a saving in the cost of upkeep, it being moreover a feature that the rotary element cannot be removed until it has made a complete revolution, that is to say until all of the fuse elements carried by it have been used.

An additional object is to provide a device of this character which will be simple and inexpensive to make, easy to install, positive in action, eflicient and durable in service and a general improvement in the art.

To the attainment of the foregoing and other objects and advantages, the invention preferably consists in the details of construction and the arrangement and combination of parts to be hereinafter more fully described and claimed, and illustrated in the accompanying drawing in which Figure l is a longitudinal sectional view through a. complete device constructed in accordance with our invention.

Figure 2 is a horizontal sectional view taken on the line 22 of Figure 1.

Figure 3 is a side elevation of the rotary member alone.

Figure 4 is a bottom plan view thereof.

Figure 5 is alongitudinal detail section taken through the rotary member alone.

Figure 6 is a fragmentary similar view showing the section taken where the retaining m0 pin is located and Figure 7 isles detail perspective view of the v contact member carried by the stap more particularly to the drawwe have shown the device as comprising a 0 formed of some suitable insulw ingsuch, asvulcanite; fiber -.is of.hrilgw fgrrn with a closed bottogd the Lowe. r ion in moreoyer,, as indicated'at 11. iin'atter'of fact it is 'sprobably preferable that thiscasiag lp be e! material of any one of numerous. l 'woll known types. Mounted upon the com V' lower end 11 of the casing is ametalmember -12 which thretdsd and j'fls heldin pliice as byhieans' 'oitis as. laanyf numberofwhich & miyfiie pno'wided Ernhedded within one side wearing the gman acture Jiisane r fi i strip f 14 one "end suitably secured to and f T e con'nected'with the shell 12 and its other end laterally deflected ant stic projecting the casing 10. "llio cated' sweetie u-ef muyuimemmu opposite 'th e uontact 15 is a pin 16 which extiids V v V one side 0f the casing 10 llnd which dedtlmrein tor a purpose to be destationary part of th'edevice includes a spring contact of substanihe i v' d U-shapef indi- V 81117 located withinthe bottom of the casing 16 and having one arm 18' lying'against bottom 19 ftliereof and secured I .-.2 lby means of wives 20. it being probfpreferable that there be a metallic a washer 21 interposedbetween the head ofthe Z '20 the bottom surface oi the insu- "19, The contact member 17 a fies abovscpi, U-s ap and s upp s i hzi ck t 2 st n a it bein quit clear th t t eh of the rivet 20, is; edepted to against afndl hefelectrica'lly connected with the cen- Y i i'taetfbfjaconventionaltype of socket ljichthe metallic, shell 12in: screwed. a r. mounted the casing 10 is 'g spindle; 23 insulating material andhaving a reduced or substantially conical v, and a 25, at its upper end, l ms vmi c g hr h nd e siqw w a b pe om d we? e P wbsxewh e sr e l aw weeni r s fiin f 27 of suitable 7 w f1 I t t the su dl t4? a ve'descri, t '2"; -M its upper portion the, member h flctthe 23 is formed with an annular groove 30 defining shoulders 31 and 32, the latter -of which is provided with a plurality of notches 33 registering with the upper ends f the -*when'itis des'iredto1emovethe s indle 23 when 111 of the fuse members 2 thereon haveheeirbiirned out or melted.

n; Lathe ration of the device, it will of I: course beo rved that it is intended to be medias-identically theeseme manner AS1 ordinaryiusezplug, that is tosay the metallic shell lfids intended to be screwed into the. usualsocket, not shown in the present case, g so tlnt tliecentral v rivet ahead en age. with ;the central contact at the set. .When this is done, it course be ap rent that ,whatever "f "A is inyi'olved w ll includeflie central 0011M 80,;the contact member orsprin contactl'f, any eno ofthe fuse members and oom- 1 apohdingelements 34. and the member 16 i which connects with the-number 14. Sup; pose; forthe sake of illustration, that one Di -Z? the elements 27 becomes burnt out, .t blowh or melted, such as will naturallyioccur inthe event of a short circuit in the line being protected, it is easily understood that whenever this occurs it is merely necessary for theoperator to grasp the handle of the portion ofthe spindle 2.3 and latter so as to bring a v ,3 contmlar and fuse member-27 into circuit e withithewontact 15. Obviously, all of" A fuse members 27 are connected with the con tactsfiuend it is quite clear that the lattd" areintended to be engageable selectively and successive! by the contact 15 so that there 7 will be; p urality of the fuse elements27 disposable in the circuit. 3

An important feature to be'noted is that the pin member 16 is adapted to en ge'the successive-notches 33 in the lower w 101 the groove in the spindle member the notches U being arranged in alinement with the fuse s 3, elements?! so that there will be no possibih ity ofen'or-in the bringing of the W 1 fuse elements 27 .into the circuit. Natumllm" when all of the fuse elements 27 have been blown or melted it is necessary that the spin tile-member 23 be replaced.v This is a simple proposition though it is intended r ply Iinfih hu'msde a full revolution? whe'it is quite clear that the pin'me m extend into the longitudinally um; wesvhensupon it is clear-3 at'ehe entire spindle member 23 together Q; with the burnt out fuse elements 27 thereon andoicourse the contacts 34 may be withs s drawn, this entire assembly being then replaced by a new one. a

From the foregoing description and a study of the drawings it will be apparent that p 5 we have thus provided a very simply constructed and easily operated device which will efiiciently perform all of the functions for which it is intended and which will operate as a material improvement in the art of renewable fuses, particularly as regards the renewability of such devices. It is thought that the construction, operation, and advantages should be readily apparent to one skilled in the art without further explanation. 7 While we have shown and described the preferred embodiment of the invention, it should of course be understood that we reserve the right to make all such changes in the details of construction as well as in the arrangement and combination of parts as will not depart from the spirit of the invention or the scope of the subjoined claims.

Having thus described the invention, we claim:

1. A renewable fuse device comprising a casing of insulating material, a metallic threaded shell member on one end of said casing adapted to be screwed into a socket, a spring contact bearing secured within said end of the casing and having a projecting element adapted to engage the central contact of a socket, a contact member embedded in the wall of said casing and connected with said shell member, a spindle of insulating material rotatably mounted within the cas- .ing, and a plurality of fuse elements carried by said spindle and radiating from a common element rotatably engaged with said spring contact bearing and having their other ends terminating in lateral extensions cooperating with said contact member embedded in the wall of the casing.

2. A renewable fuse device comprising a casing of insulating material, a metallicthreaded shell member on one end of said casing adapted to be screwed into a socket, a spring contact secured within said end of the casing formed with a bearing and having a projecting element adapted to engage the central contact of a socket, a contact member embedded in the wall of said casing and connected with said shell member, a spindle of insulating material rotatably mounted within the casing, and a plurality of fuse elements carried by said spindle and radiating from a common metallic element rotatably engaged within said bearing and having their other ends terminating in lat- I E eral extensions cooperating with said second named contact, and detent means projecting radially through the side of the casing and cooperating with notches in the interior of said spindle for maintaining the same in a selected rotatably adjusted position.

e 3. A renewable fuse device comprising a casing of insulating material, a metallic threaded shell member on one end of said casing adapted to be screwed into a socket, a spring contact formed with a bearing secured within said end of the casing and having a projecting element adapted to engage the central contact of a socket, a contact mem: ber embedded in the wall of said casing and connected with said shell member, a spindle of insulating material rotatably mounted within the casing and carrying a metallic element engaged within said bearing, and a plurality of fuse elements carried by said spindle and radiating from said metallic element and in electrical contact therewith and having their other ends engageable with said contact embedded in the wall of the casing, a detent element carried by the side of the casing and projecting into the interior thereof, said spindle having a peripheral groove accommodating said detent element and provided at the bottom of the groove with a plurality of notches corresponding to said fuse elements and adapted to receive the detent element.

' LA renewable fuse device comprising a casing of insulating material, a metallic threaded shell member on one end of said casing adapted to be screwed into a socket, a spring contact secured within said end of the casing and having a projecting element adapted to engage the central contact of a socket, a contact member embedded in the wall of said casing and connected with said shell member, a spindle of insulating material rotatably mounted within the casing, and a plurality of fuse elements carried by said spindle and radiating from a common point rotatably engaged with said spring contact and having their other ends terminating in lateral extensions cooperating with said contact embedded in the Wall of the casing, a detent element carried by the casing and projecting into the interior thereof, and said spindle having a peripheral groove accommodating said detent element and provided at one side with a plurality of notches corresponding to said fuse elements and adapted to receive the detent element, said spindle further having a longitudinal groove leading into said peripheral groove for receiving said detent element to permit withdrawal and replacement of the spindle.

5. A renewable fuse device comprising a casing of insulating material, a metallic threaded she'll member on one end of said casing adapted to be screwed into a socket,

a spring contact secured within said end of the casing and having a projecting element adapted to engage the central contact of a socket, a contact member embedded in the wall ofsaid casing and connected with said shell member, a spindle of insulating material rotatably mounted within the casing, and a plurality of fuse elements carried by 

